Riser pipe stacking method

ABSTRACT

An offshore drilling rig that embodies a means for vertical stacking of riser pipe sections and blowout preventors below a derrick floor and includes riser pipe manipulating mechanisms for transporting units in a vertical condition between a storage area and the operational area. In the operational area, the cellar floor is provided with a sliding door mechanism which is selectively capable of supporting either the blowout preventor and riser weight, or the blowout preventor. The transportation system includes means for lifting and supporting a riser pipe section vertically and movable in transverse and longitudinal, horizontal directions for transporting pipe sections in a vertical condition.

United States Patent [191 [111 3,895,677

Bokenkamp 1 July 22, 197 5 1 RISER PIPE STACKING METHOD 3,333,562 8/1967Deal et al. 114/.5 n

t D ld G. B kenka Houston,

[75] Inven or 'l it 0 mp Primary Examiner-Ernest R. Purser [73]Assignee: Dolphin International, Inc., I ABSTRACT Houston, Tex. Anoffshore drilling rig that embodies a means for ver- [22] Filed 1974tical stacking of riser pipe sections and blowout pre- [21] Appl. No.:434,651 ventors below a derrick floor and includes riser pipemanipulating mechanisms for transporting units in a vertical conditionbetween a storage area and the op- [52] 166/5; 166/315; 47 erationalarea. In the operational area. the cellar floor is provided with asliding door mechanism which is se- [51] CLZ E21B 19/14 lectivelycapable of supporting either the blowout pre- Field of Search 166/ 5 315175/5 ventor and riser weight, or the blowout preventor. The

transportation system includes means for lifting and supporting a riserpipe section vertically and movable in transverse and longitudinal,horizontal directions [56] References Cited for transporting pipesections in a vertical condition.

UNITED STATES PATENTS 3,043,255 7/1962 Bauer et al. 114/.5 D 4 Clams 8Draw 3,189,093 6/1965 De Vries 166/.5

PATENTEDJUL22 1315 3.895577 SHEET 2 FIG. 2 20 19A FIG. 3

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PATENTEDJUL 22 I975 3,895,677 SHEET 3 squ 5pc 50 40 =1 l I I I I lli Ix!" I .m'

pi I mil FIGS RISER PIPE STACKING METHOD BACKGROUND OF THE INVENTIONdition below the derrick floor and for transporting such units invertical condition between storage and operational areas.

In offshore drilling rigs, it is customary to have a string ofinterconnected tubular pipe sections extending from the rig to a blowoutpreventor means (sometimes hereinafter referred to as BOP) set on theocean floor. The drilling string is then inserted through the tubularpipe string (called a riser) for the drilling of the earth formationsbelow the ocean floor.

On most rigs during the installation or removal of a riser pipe system,the riser is set or supported dependently on the rotary table andconnections of riser pipe sections are made at the rig or derrick floorlevel. When not in use, the lengths of riser pipe sections are usuallypassed through a V-door and supported horizontally on a pipe rack bymeans of a rig crane. This manipulation of riser pipe sections between ahorizontal position on a pipe rack and a vertical passage through therotary table is similar to the operation required for running casingstrings. The operation requires virtually the full drilling crew as wellas crane operators and roustabouts.

During rough weather, the riser sections are hard to control whilehanging on the crane-sling lines. Tag lines are an aid but the chancefor injury to personnel or damage to the riser is great. Actually, theproblem of retrieving riser sections often comes about because of badweather where it is desired to pull the riser string.

In the present invention, enough clearance is provided between a lowercellar deck and the derrick floor to rack or store the riser sectionsvertically under the derrick floor. The advantages of this conceptinclude:

I. The need to lay down the riser pipe joints on the pipe rack iseliminated;

2. Wind or dynamic loading on the derrick is not increased as it wouldbe if the riser were racked in the derrick;

3. More pipe rack area is available for other tubulars;

4. The hazard to equipment and personnel created by frequent cranehandling is eliminated;

5. The same storage area is used for transit that is used while pullingor running;

6. The number of personnel required to handle the riser is reduced;

7. The time necessary to run or pull the riser is decreased; and

8. The capability for handling the riser in more severe weather isincreased.

SUMMARY OF THE INVENTION floor to the riser storage area. In thisregard, the transportation system has capability for transverse andlongitudinal, horizontal directional movement and vertical liftingmovement. Means are provided for independent motion in any of the threecoordinate directions. The transportation means include a bridge typecrane mounted for movement on a pair of rails. A vertical lifting deviceis mounted for sliding movement along a transverse beam of the crane. Atthe cellar floor opening is a first pair of supporting arms for engagingand supporting blowout preventors where the supporting arms are spacedat appropriate distances relative to blowout preventors sizes. At thecellar floor opening also is a second pair of supporting arms forengaging and supporting riser pipe sections. The separate pair ofsupporting arms utilize the same space but can be selectively employed.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become moreapparent when the following description is taken in connection with thedrawings in which:

FIG. 1 is a schematic representation of an offshore rig embodying theriser pipe handling system of the present invention;

FIGS. 24 are plan views of the door and opening in extended andretracted positions;

FIG. 5 is a view taken along line 5-5 of FIG. 3;

FIG. 6 is a side view taken along line 66 of FIG. 7;

FIG. 7 is a plan view of the transporting system for riser pipe and BOPmeans; and

FIG. 8 is a schematic illustration of the cellar floor plan fortransporting and storing riser pipe sections.

DESCRIPTION OF THE INVENTION Referring now to FIG. 1, an offshore rig ordrilling barge 10 which can be a semi-submersible which supports adrilling floor 11 above the surface 12 of the ocean 13. Below thedrilling floor 11 is a cellar deck or floor 14. The clearance betweenthe cellar floor 14 and drilling floor 11 is made adequate to permitvertical stacking of riser pipe sections between the two floors l1 and14. On the drilling floor I1 is a derrick l5 equipped with a travelingblock 16, draw works 17, and a rotary table 18. Vertically aligned withthe rotary table 18 is an opening 19 (sometimes called a moon poolopening) in the cellar floor 14. A special two-stage horizontallymovable door 20 is movable between an extended position over the openingto support selectively either a riser pipe section or a Blow OutPreventor (hereinafter referred to as BOP). The door 20 is powered bysuitable hydraulic or mechanical means which is schematicallyillustrated by the numeral 21. The door powering means 21 is capable ofhorizontally reciprocating the door 20 relative to the opening 19between an extended position over the opening or a retracted positionwhere the opening is entirely clear. As illustrated in FIG. 1, a riserpipe string 22 is extended from the cellar floor 14 to the ocean floor23. The riser string 22 is comprised of the usual tubular riser pipesections or joints which are connected to one another. At the bottom ofthe riser string is a BOP means 24 which attaches to the ocean floorwell head connection. The BOP means 24, as illustrated, has an enlargedcross-section as compared to the cross-section of a riser pipe section.The vertical clearance between the cellar floor and derrick floor issuch that one of the riser pipe sections 25 can be vertically disposedin the clearance between the rotary table 18 in the drilling floor andopening 19 in the cellar floor. The riser pipe sections and BOP meanshave support means (to be explained later) which are engagable by thedoor 20 to support the riser string 22 while a riser pipe section 25 isadded or subtracted from the riser pipe string.

Means for moving a riser pipe section in the space between the drillingrig floor and cellar floor include a bridge crane 27 which is mountedfor movement in one horizontal direction by spaced apart guide rails 28(only one shown). The crane includes wire lines 29 for moving the BOPmeans vertically with respect to the cellar floor. A transverse beam 30on the bridge crane extends between the guide rails 28. A fork lift typedevice 31 is mounted for movement along the length of the beam 30 and isalso capable of vertical movement relative to the transverse beam 30.The purpose of this arrangement is to transport riser pipe sections orBOP means in a vertical condition between the cellar opening 19 andstorage areas. The storage area for the BOP means is to either side ofthe opening as shown by the illustration of upper and lower BOP stacks32 and 33. The storage area for the riser pipe sections includes upperfingers 35 which are arranged to receive the upper portion of the riserpipe sections and stubs 36 set along the cellar floor for receiving theopen lower end of each riser pipe section.

In the overall operation of the system, the crane 2 first picks up thelower section 33 of a BOP and moves it to the opening 19. The BOPportion 33 is lowered partially through the opening with the door 20 ina retracted condition. Then, the door 20 which has beams for supportingthe BOP 33, is moved to an extended position where the door arms supportthe BOP portion 33 relative to the cellar floor. The bridge crane 27 isthen used to move the upper BOP section 32 over the lower section andthe BOP sections are connected. After connection of the upper BOPsection 32 to the lower BOP section 33, a single joint of riser pipethat has been prepositioned on the hook of the traveling block 16 bymeans of a running too] (not shown) is lowered through the rotary table18 and connected to the top of the assembled BOP stack. The BOP stack isthen picked up sufficiently for clearance and the sliding door 20 isretracted to allow passage through the cellar deck opening 19 of theBOP. After the BOP has been sufficiently lowered to clear the cellardeck opening 19, a second pair of door arms are engaged to the first setof door arms that previously supported the BOPs. The interconnection ofthe two sets of arms is accomplished while the door is in the retractedposition. The door 20 is then manipulated again to an extended positionwith the now interconnected second set of arms that are spaced apartsufficiently to provide clearance for the riser and to support a riserspider 37 which will support the riser section and BOP connected to it.The riser spider 37 is then installed around the riser and supported bythe second set of arms. The riser is then set in it. The running tool(not shown) is then released and pulled up sufficiently to provideclearance for the next joint of riser. The fork lift device 31 is movedto the riser pipe section storage area and another riser pipe section ispicked up vertically and transported in a vertical condition to thecellar opening 19 where it is lowered and coupled to the riser jointsetting in the riser spider. The running tool (not shown) attached tothe traveling block 16 is lowered through the rotary table 18 to attachto the connected riser pipe section. After connection with the runningtool, the assembled stack is picked up sufficiently to release thespider and then is lowered until the second riser pipe section is inposition to be supported by the riser spider 37. This sequence isrepeated for the other riser pipe sections as needed. The operation isreversed for pulling the riser string.

Referring now to FIGS. 2-5, the door 20 and opening 19 are shown ingreater detail. The opening 19 is defined by a rectangular shaped framecomprised of frame components 19(A-D) which attach to the cellar floor.The side frame components or members 19a and are elongated and attachedto an end frame member 1%. In FIG. 2, the door 20 is in a retractedposition and rests upon the frame members 19c, 19a, 19c and 19d. Thedoor 20 includes two sets of generally U- shaped gate members. A firstU-shaped member 40 is shown most clearly in FIG. 3. The gate member 40has a length greater than the span between the frame members 19d and19c, and its open end lies on the transverse frame member 19d in theretracted position of the gate member. The U-shaped gate member 40includes a pair of longitudinally extending bar members 40a and 40bwhich are spaced apart a distance compatable with the outer diameter ofa riser pipe section so that ariser pipe section can be supported by ariser spider installed on the gate member 40. For supporting riser pipesections, a conventional riser pipe spider is also employed but is notshown for clarity of illustration.

The other U-shaped gate member 50 is also shown most clearly in FIG. 3.The gate member 50 has its open end facing the opening 19 where the openend is defined by parallel bar members 50a and 50b. The bar members 50aand 50b are spaced apart a distance compatable with the outer diameterof a BOP. The bar members 50a and 50b attach toa pair of spacedtransverse bars 50c and 50d which extend across the width of the framemember 19d. Side support bar members 50c and 50f extend along the lengthof the frame members 29a and 19c and attach to the BOP supporting bars50a and 50b. As illustrated in FIGS. 2 and 3, the gate member 50 ismovable between a retracted and extended position relative to the cellaropening 19. Mean (such as tongue and groove connections not shown) areprovided for suitable guiding of the gate members relative to the frame.The gate member 50 has its transverse members 50c and 50d disposed abovethe bars 40a and 40b (see FIG. 5) of the gate member 40 so that the gatemembers 40 and 50 may move horizontally between retracted and extendedpositions independently of one another. Selective locking means in theform of openings 40c and 50g are respectively provided in the bars 40aand 40b and the transverse bars 50c and 50d. Pins (not shown) are usedto couple the gate members to one another. Hence, as shown in FIG. 4,both gate members 40 and 50 can be retracted and extended relative tothe opening 19 in unison.

A riser spider 37 is conventional and is shown schematically in FIG. 4.The spider 37 includes hinged semi-cylindrical members with fourequidistantly spaced latching fingers-37a. The latching fingers 37areleasably engage latching slots in a riser section for plan view. Theguide rails 28 are spaced from one another in a parallel fashion at theheight above the cellar floor adequate to permit transportation of ariser pipe section in a vertical condition. Elongated end frame members61 and 62 extend along the rails and carry journaled pairs of wheels 63.The frame members 61 and 62 are connected to transverse beam members 64and 65 which can have box type cross-sections. The frame and beammembers 61, 62, 64 and 65 form a generally rectangular configurationwhich is movable in a horizontal direction by virtue of the wheels 63and the track 28. A longitudinal rack 66 can be attached to one or bothof the rails 28. A pinion 67 on the wheel shaft 68 engages the rack 66for driving purposes. A motor and transmission means'69 on the beam 64can be used to drive the shaft 68. As shown in FIG. 6, one or more hooks29 attached to cable and spooling means 70 can be provided on the framefor picking up equipment such as the BOP means.

On the forward transverse beam 65, its upper and lower surfaces areprovided with longitudinally extending guides 71, 72 and 73. A U-shapedframe member 74 has an upper arm with a vertically journaled set ofrollers 75 which engage a side of the guide 71 facing away from thefront of the beam 65. Horizontally journaled sets of rollers76 in theframe 74 engage the upper surfaces of the guides 71 and 73. A verticallyjournaled roller in the lower arm of the frame member 74 engages anouter side of the lower guide 72. The guides and rollers provide acantilevered rolling support for the frame member 74 on the transversebeam 65. A motor 77 on the frame member operates a pinion on the framemember 74 which engages a longitudinal rack 78 on the beam 65. Operationof the motor 77 traverses the frame member 74'relative to the beammember 65 in a horizontal direction transverse or perpendicular to thedirection of travel of the beam member 65 on the rails 28.

The foward portion of the frame member 75 is provided with parallelvertical trackways 80 in opposing sides of the frame member. Guiderollers 81 are received in the guideways and are attached to a liftingframe 82. Additional side rollers 83 are provided so that the liftingframe 82 is movable vertically with respect to the frame member 74.Hydraulic means 84 are coupled between the frame member 74 and liftingframe 82 to accomplish relative vertical motion between the units. Thelifting frame 82 has a generally flat upper surface 86 which has aU-shaped recess 87 sized to pass around the outer diameter of a risersection. A riser pipe section 24 has diametrically opposed pin members88 perpendicularly arranged relative to the axis of a riser pipe andsupported by plate members 89 welded to the upper sides of the pins 88and to the sides of a riser pipe section. The surface 82 of the frame 82has recesses 90 therein to receive the pins 88 so that a riser sectionis interlocked by the pins to the lifting frame.

As shown in FIG. 8, the arms 35 which provide the upper support for theriser pipe sections can include transverse locking bars 92 to retain theupper portion of the pipes in a steady condition. The crane 27 can moveto the stored riser pipe sections and the fork lift device can belowered below the crane 27 to engage the pins 88 of a riser pipesection. The arms 35 for storage are located relative to the pins 88 sothat the lifting portion of fork lift device can be inserted between thearms 35 and pins 88. The riser pipe sections are stacked and removed oneat a time from side to side of the racking arms 35.

In summary of the overall operation of the system, the crane 27 firstpicks up the lower end 33 of a BOP and moves it to the opening 19. TheBOP portion 33 is lowered partially through the opening 19 with the doorsections 40 and 50 in a retracted condition. Then, the door section 50which has beams for supporting the BOP 33, is moved to an extendedposition where the door section 50 supports the BOP portion 33 relativeto the cellar floor. The bridge crane 27 is then used to move an upperBOP section 32 over the lower section 33 and the BOP sections 32 and 33are connected. After connection-of the upper BOP section 32 to the lowerBOP section 33, a single joint of riser pipe that has beenpre-position'ed on the hook of the traveling block 16 by means of arunning tool (not shown) is lowered through the rotary table 18 andconnected to the top of the asembled BOP stack. The BOP stack is thenpicked up sufficiently for clearance and the door sec tion 50 of thesliding door 20 is retracted to allow passage through the cellar deckopening 19 of the BOP. After the BOP has been sufficiently lowered toclear the cellar deck opening 19, a second pair of door arms 40 areengaged to the first set of arms 50 that previously supported the BOPS.The interconnection of the two sets of arms 40 and 50 is accomplished byinserting pins in the holes 40c and 50g while the door is in theretracted position. The door 20 is then manipulated again to an extendedposition with the now engaged second set of arms 40 that are spacedapart sufficiently to provide clearance for the riser and to support ariser spider 37 which will support the riser and BOP connected to it.The riser spider 37 is then installed around the riser and supported bythe second set of arms 40. The riser is then set in it. The running tool(not shown) is then released and pulled up sufficiently to provideclearance for the next joint of riser. The fork lift device 31 is movedto the riser pipe section storage area and another riser pipe section ispicked up vertically and transported in a vertical condition to thecellar opening 19 where it is lowered and coupled to the riser jointsetting in the riser spider. The running too] (not shown) attached tothe traveling block 16 and is lowered through the rotary table 18 toattach to the connected riser pipe section. After connection with therunning tool, the assembled stack is picked up sufficiently to releasethe spider and then is lowered until the riser pipe section is inposition to be supported by the riser spider which is supported by thedoor section 40. The door section 40 then supports the depending stackby support of the riser pipe section by the door sections 40 and 50coupled to one another.

While particular embodiments of the present invention have been shownand described, it is apparent that changes and modifications may be madewithout departing from the invention in its broader aspects; andtherefore, the aim in the appended claims is to cover all such changesand modifications as fall within the true spirit and scope of thisinvention.

What is claimed is:

1. In an offshore drilling system on location in a body of water, amethod for manipulating riser pipe sections between a stored conditionof individual sections in a storage area in a drilling rig and anoperational condition of sections coupled to one another to define ariser string where said riser string extends downwardly from thedrilling rig toward the floor under the water, said method comprisingthe steps of coupling the draw works of a drilling rig to the riserstring and lifting the riser string through an opening in a riserstorage floor until at least the upper end of said riser string is belowthe rotary table on the rig floor and at least one riser section isabove the riser storage floor,

releasably supporting the riser string at said opening in said riserstorage floor, releasably coupling a horizontally movable transfer meansto the upper end of a riser section just below the rotary table,disconnecting the draw works from the riser string and disconnectingsuch riser pipe section from the riser string at a location above saidopening, raising such uncoupled riser pipe section on the horizontaltransfer means to clear the end of the supported riser string andtransferring such uncoupled riser pipe section in a horizontal directionwhile in a vertical condition to a storage area on the same level, atsuch storage area, lowering such uncoupled riser pipe section withrespect to the horizontal transfer means into a storage position on apipe rack, and

securing such uncoupled riser pipe section to said pipe rack.

2. The method as defined in claim 1 snd further including theperformance of the following steps while a riser pipe section is beingmoved to the storage area,

coupling the draw works of the drilling rig to the supported riserstring immediately following the initiation of the transfer of anuncoupled riser pipe section to the storage area, releasing the supportof said riser string at said opening and lifting the riser stringthrough said opening to position at the next riser section in the riserstring above the riser storage floor, and

releasably supporting the riser string at said opening in said riserstorage floor.

3. In an offshore drilling system on location in a body of water, amethod for manipulating riser pipe sections between a stored conditionof individual sections in a storage area in a drilling rig and anoperational condition of sections coupled to one another to define ariser string where said riser string extends downwardly from thedrilling rig toward the floor under the water, said method comprisingthe steps of moving a riser pipe section from a storage area to alocation below a draw works,

coupling the draw works to such riser pipe section and raising the riserpipe section into the drilling rig,

moving a blow out preventer from a storage area to a location below thedraw works,

supporting the blow out preventer at the opening in a riser pipe storagefloor, and lowering the raised riser pipe section to said blow outpreventer,

coupling said riser pipe section to said blow out preventer,

coupling the blow out preventer to the riser pipe sec tion, releasingthe support for the blow out preventer and lowering the riser pipesection and blow out preventer through the opening in the riser storagefloor until at the upper end of said riser pipe section is just abovethe riser storage floor,

releasably supporting the riser pipe section at said opening in saidriser storage floor,

releasably coupling a horizontally movable transfer means to the upperend of another riser section, disconnecting the draw works from theriser pipe section, and connecting such other riser pipe section to theriser section in the opening to define a riser string depending fromsaid opening,

coupling the draw works to said riser string, releasing the support atsaid opening and lowering said riser string to a location where theupper end of the riser string is just above said opening, and

releasably securing such riser string in said opening.

4. The method as defined in claim 3 and further including theperformance of the following steps while the riser pipe string islowered through said opening, the steps of coupling a horizontallymovable transfer means to a pipe section in a storage area on the riserstorage floor and transferring such pipe section toward said openingwhile said pipe string is being lowered through said opening.

1. In an offshore drilling system on location in a body of water, amethod for manipulating riser pipe sections between a stored conditionof individual sections in a storage area in a drilling rig and anoperational condition of sections coupled to one another to define ariser string where said riser string extends downwardly from thedrilling rig toward the floor under the water, said method comprisingthe steps of coupling the draw works of a drilling rig to the riserstring and lifting the riser string through an opening in a riserstorage floor until at least the upper end of said riser string is belowthe rotary table on the rig floor and at least one riser section isabove the riser storage floor, releasably supporting the riser string atsaid opening in said riser storage floor, releasably coupling ahorizontally movable transfer means to the upper end of a riser sectionjust below the rotary table, disconnecting the draw works from the riserstring and disconnecting such riser pipe section from the riser stringat a location above said opening, raising such uncoupled riser pipesection on the horizontal transfer means to clear the end of thesupported riser string and transferring such uncoupled riser pipesection in a horizontal direction while in a vertical condition to astorage area on the same level, at such storage area, lowering suchuncoupled riser pipe section with respect to the horizontal transfermeans into a storage position on a pipe rack, and securing suchuncoupled riser pipe section to said pipe rack.
 2. The method as definedin claim 1 snd further including the performance of the following stepswhile a riser pipe section is being moved to the storage area, couplingthe draw works of the drilling rig to the supported riser stringimmediately following the initiation of the transfer of an uncoupledriser pipe section to the storage area, releasing the support of saidriser string at said opening and lifting the riser string through saidopening to position at the next riser section in the riser string abovethe riser storage floor, and releasably supporting the riser string atsaid opening in said riser storage floor.
 3. In an offshore drillingsysTem on location in a body of water, a method for manipulating riserpipe sections between a stored condition of individual sections in astorage area in a drilling rig and an operational condition of sectionscoupled to one another to define a riser string where said riser stringextends downwardly from the drilling rig toward the floor under thewater, said method comprising the steps of moving a riser pipe sectionfrom a storage area to a location below a draw works, coupling the drawworks to such riser pipe section and raising the riser pipe section intothe drilling rig, moving a blow out preventer from a storage area to alocation below the draw works, supporting the blow out preventer at theopening in a riser pipe storage floor, and lowering the raised riserpipe section to said blow out preventer, coupling said riser pipesection to said blow out preventer, coupling the blow out preventer tothe riser pipe section, releasing the support for the blow out preventerand lowering the riser pipe section and blow out preventer through theopening in the riser storage floor until at the upper end of said riserpipe section is just above the riser storage floor, releasablysupporting the riser pipe section at said opening in said riser storagefloor, releasably coupling a horizontally movable transfer means to theupper end of another riser section, disconnecting the draw works fromthe riser pipe section, and connecting such other riser pipe section tothe riser section in the opening to define a riser string depending fromsaid opening, coupling the draw works to said riser string, releasingthe support at said opening and lowering said riser string to a locationwhere the upper end of the riser string is just above said opening, andreleasably securing such riser string in said opening.
 4. The method asdefined in claim 3 and further including the performance of thefollowing steps while the riser pipe string is lowered through saidopening, the steps of coupling a horizontally movable transfer means toa pipe section in a storage area on the riser storage floor andtransferring such pipe section toward said opening while said pipestring is being lowered through said opening.